Self activated fluidic control for a submerged towed body

ABSTRACT

A bi-stable fluidic amplifier is inserted in a towed body. The nose of the towed body is opened to admit fluid, which is funnelled under the force of the flow stream into the fluidic amplifier. A passive pressure sensor, preset to a desired depth or altitude controls the direction of the fluid leaving the fluidic device through exit conduits connected from the fluidic device, one to the upper and one to lower surface of the towed body. These exit lines terminate at approximately the separation point of the fluid flowing around the body. The pressure regulator reacting to changes in depth directs a control signal to the fluidic amplifier to divert the passage of the fluid to either the upper or lower exit conduits, depending upon the pressure. Fluid from an exit port is entrained back along the side of the body causing the separation point on that side of the body to move back along the body thereby increasing lift on that side of the body. The change in the lifting force on one side of the body without an equal change on the opposite side forces a change in the attitude or angle of attack of the body to the fluid so it will either plane towards the surface or dives, until the body reaches the pressure level preset on the pressure sensor.

United States Patent J oynes [54] SELF ACTIVATED FLUIDIC CONTROL FOR A SUBMERGED TOWED BODY [72] Inventor: John L. Joynes, Annapolis, Md.

[73] Assignee: The United States of represented by the Secretary of the Navy 22 Filed: NovLZS, 1970 [21] Appl.No.: 92,751

52 user ..131/s1.s,73/17s [51] InLCI. [58] Field oiSearch Warren et al.

Duncan America as [451 July 18, 1972 Primary Examiner-Samuel Scott Attorney-R. S. Sciascia and Q. E. Hodges [57] Y ABSTRACT A bi-stable fluidic amplifier is inserted in a towed body. The nose of the towed body is opened to admit fluid, which is funnelled under the force of the flow stream into the fluidic amplifier. A passive pressure sensor, preset to a desired depth or altitude controls the direction of the fluid leaving the fluidic device through exit conduits connected from the fluidic device, one to the upper and one to lower surface of the towed body. These exit lines terminate at approximately the separation point of the fluid flowing around the body. The pressure regulator reacting to changes in depth directs a control signal to the fluidic amplifier to divert the passage of the fluid to either the upper or lower exit conduits, depending upon the pressure. Fluid from an exit port is entrained back along the side of the body causing the separation point on that side of the body to move back along the body thereby increasing lift on that side of the body. The change in the lifting force on one side of the body without an equal change on the opposite side forces a change in the attitude or angle of attack of the body to the fluid so it will either plane towards the surface or dives, until the body reaches the pressure level preset on the pressure sensor.

5 Claim, 3 Drawing Figures DESCRIPTION OF THE PRIOR ART Towed bodies can be controlled by conventional rudder or foil systems. These control systems are usually actuated by pneumatic, hydraulic or electrical power. Such systems require large, heavy prime movers and batteries or high pressure air storage tanks. Additionally, the systems require gearing to increase the system torque to a level sufficient to move the rudder or the foil. These systems beside depending upon a central power source within the towing vehicle and/or heavy cables to communicate electrical or pneumatic power from the vehicle to the towed body, usually in water require seals for protection. But water protection is expensive to obtain and difficult to maintain. In addition, most towed bodies carry instrumentation. Also many towed bodies require the control system to be maintained in the towing vehicle or require data sensors located on the towed body, lines for communication between the data sensors and the control system in the towing vehicle and communication lines from the control system back to the towed body. While it is usually desired to keep the size of the towing cable to the smallest possible size to minimize drag, it is impossible to transmit high power, electrical control signals or pneumatic energy through long tow cables without increasing the cable size and drag.

SUMMARY OF THE INVENTION A bi-stable fluidic amplifier is inserted in a towed body. The amplifiers input fluid stream is obtained through an opening in the nose of the towed body, admitting fluid under the pressure of the flow stream into the fluidic amplifier. A passive spring operated pressure sensor and regulator is preset to a predetermined depth. Any changes in the depth of the towed body from the preset depth is converted to an appropriate command by the sensor regulator and transmitted to the fluidic amplifier through one of two control lines connected from the regulator to the fluidic amplifier fluid interaction chamber. The fluid supply for the pressure regulator is obtained from the fluidic devices inlet conduit. The regulator, in response to pressure changes channels control fluid to an appropriate control line, which then diverts the fluid passing through the fluidic amplifier to one of the exit conduits. The exit conduit terminates in exit ports at the surface of the towed body just before the flow separation region. Fluid emitted by the exit ports is entrained back along the side of the body causing the separation point to move further aft, increasing the lifting force on that side. The force of the increased lift on the body causes a change of attitude of the body to either a surfacing attitude or a diving attitude, depending on which side of the body the fluid is emitted.

This system is completely self contained and requires only a towing cable connected between the towing vehicle and the towed body. Additionally, its only moving part is a passive spring loaded pressure regulator, and it requires no internal power sources as it derives its power from the flow of fluid through and around the towed body.

This device could be equally well used in air liquid or in other fluid environments.

Accordingly, one object of this invention is a self contained towed vehicle control system.

A second object is a control system deriving its power from its flow stream.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows in cross-section a first embodiment of th device according to the principles of the invention.

FIG. 2 shows in cross-section a second embodiment of the device according to the principles of the invention, and with the same reference numbers used in FIG. 1 denoting the same and similarly operating elements.

FIG. 3 shows in cross-section a third embodiment according to the principles of this invention, with the same reference numbers denoting the same and similarly operating parts.

DESCRIPTION OF PREFERRED EMBODIMENT Referring now to FIG. 1 wherein is shown the towed body 10 having a fixture 13 for connection to a towing cable 11 for towing in the direction shown by the arrow 12. The forward section of the towed body has a conical opening 15 designed to funnel water into the body as the body moves in the direction of arrow 12. A conduit 17 connects the conical opening 15 to pressure-sensor regulator 19. The regulator 19 contains a transducer 18 in contact with the seawater environment surrounding the towed body and senses the pressure corresponding to a depth of the body. A conduit 21 connects the conical inlet 15 with the bi-stable fluidic amplifier 22. The bistable fluidic amplifier has a fluid interaction chamber 23, a control line inlet 24 and a control line inlet 26. Low volume/low pressure fluid is emitted bythe pressure sensor regulator 19 through either control line 25 or control line 27 to control port 26 or control port 24, respectively. The main stream entering from conduit 21 into the fluid interaction chamber 23, exits through exit conduit 29, opening into exhaust port 33 or exit conduit 31, opening into exhaust port 35, as will be hereinafter explained.

The exit ports 33 and 35 are located in flow separation regions 37 and 39 on the top and bottom of the submerged vehicle, respectively. The exit ports 33 and 35 are shaped to emit a stream of fluid in the alt direction and along the surface of the towed body.

OPERATION This device is designed to maintain towed body 10 at or near a specific depth. Passive spring pressure sensor-regulator 19 is preset to the desired upper and lower depth limits.

Ifthe towed body rises to a depth less than the desired upper depth limit to which the regulator 19 is set, the regulator will emit a low volume, low pressure fluid through conduit 27 where it will enter the fluid interaction chamber at port 24. The effect of this fluid stream at port 24 is to divert substantially all of the stream, entering the fluidic device through conduit 21, through exit conduit 29 and out exit port 33. The fluid emitted from port 33 is entrained back along the sides of the towed body in region 37, increasing the lift force on the upper after portion of the towed body. As'the inlet stream is substantially diverted to flow through conduit 29, little or no fluid will flow through conduit 31. The net effect from the change in lift force will be to rotate body 10, changing its angle of attack to a diving angle. The towed body will then dive until the desired lower depth limit is reached where pressure regulator 19 will stop the flow of the control fluid through conduit 27, stopping the flow through conduit 29.

If the body drops to a depth below its lower depth limit, the higher pressure sensed by 18 will be communicated to the regulator 19. Regulator 19 will emit a low volume, low pressure fluid through conduit 25 to the fluid interaction chamber where it will divert the incoming stream through conduit 21 to conduit 31 and exit port 35. With the inlet stream from conduit 21 substantially diverted through exit conduit 31, the lift in region 39 increases as the water emitted from exit conduit 35 is now entrained along the towed body surface region 39, increasing its lift over that portion. The body under the force of the increased lifting force in region 39 will experience a change in angle of attack as the body is rotated into a surfacing position. The towed body will then rise to the upper desired depth limit where the fluid flow through conduit line 25 will be cut off and fluid flow through conduit 27 will begin and the diving cycle begins again.

Referring now to FIG. 2, is seen a second embodiment 20, according to the principles of the invention. This embodiment is substantially the same as the embodiment shown in FIG. 1 with the exception of spoiler conduit 41 extending fromexit conduit 31 to spoiler exit port 45 and spoiler conduit 43 extending from exit conduit 29 to spoiler port 47. The embodiment shown in FIG. 2 operates substantially as the embodiment shown in FIG. 1 with the exception that spoiler conduits 41 and 43 divert fluid from conduits 31 and 29, respectively. This fluid from exit port 45 is emitted substantially in direction opposite the flow stream across the towed body. When the body 20 is at the depth below the desired depth, fluid is diverted through exit conduit 31 to increase the lift in area 39 and to rotate the body 20 into a surfacing attitude. Fluid is partially diverted from exit conduit 31 through exit conduit 41 where it is emitted from spoiler exit ports 45 to increase the flow separation in region 37 and further decrease the lift over the region 37. The increased lifting force on surface 39 acts as a couple with the decreased lifting force in region 37, increasing the force changing the angle of attack of the body 20. In a similar manner, fluid is partially diverted from exit conduit 29, through spoiler conduit 43 when the towed body 20 is above its desired depth and increased lift is desired in region 37 and decreased lift is desired in region 39 to change the angle of attack of the body to a diving angle. To increase the effect of the spoiler flow, a series or area of ports may be used in place for single spoiler exit port.

Referring now to H6. 3, wherein is shown a third embodiment 30, according to the principles of this invention, operating substantially as the embodiment shown in FIG. 1. Towed body 30 is similar in respect to towed body with the exception that the fluid entering the fluid interaction chamber 23 exits in the absence of control fluid emitted through control lines 25 and 27, substantially through exit conduit 61. When the towed body 30 is at a depth above the desired depth and it is desired to increase the lift in region 37, the pressure regulator l9 emits the low pressure, low volume control fluid through conduit 27 and port 24 into the fluid interaction chamber, diverting the flow stream from conduit 21 substantially through exit conduit 53. The flow of fluid past the intersection of intake conduit 52, with exit conduit 53, produces a low pressure area in conduit 52, drawing fluid in from the flow separation region 37 As fluid is drawn in from the separation region, the region is moved further aft on the towed body increasing the lift over area 37. The increased lifting force over region 37 rotates towed body 30 to a diving position and the towed body is then pulled to the lower desired depth at which pressure regulator 19 will cut off the supply of control fluid through conduit 27 and the towed body will level out. Similarly, if the towed body 30 is at a lower depth than the desired depth, pressure regulator 19 emits low pressure, low volume control fluid through conduit 25 to the fluid interaction chamber at port 26. The flow stream from conduit 21 is then substantially diverted through exit conduit 57. The flow of fluid past where it produces a low pressure, the intersection of exit conduit 57 and intake conduit 54 produces a low pressure in conduit 54. Fluid from the stagnation region 39 is then pulled in through intake port 49 and is entrained with the fluid stream in conduit 57. As fluid is drawn from the flow separation region is moved further aft along the towed body increasing the lift over region 39 and rotating the body 30 into a surfacing position where it then rises to a desired depth and levels off.

Although a bi-stable fluidic device has been shown in FIGS. 1 and 2, a proportional pressure sensor and a proportional output fluidic device with an additional output conduit 28, operating in the same way as conduit 61, could be used to change the angle of attack of the towed body proportionally to its depth. To convert the bi-stable embodiments shown in FIGS. 1 and 2 to a proportional output device, all that is necessary is to add a third exit conduit 28 (shown in dashed lines), extending from the interaction area 23 and in a direction parallel to the fore-aft line of the body, to channel the input fluid from conduit 21, in the absence of control fluid. Also, this mode of control can be used on other towed vehicles in other fluid mediums, for example, in air planes or in helicopters when towing an instrument package that it is desirable to keep a fixed distance above the sea or land.

Although this invention has been shown to produce changes in lifting forces on the top and bottom of the body causing a predetermined response in body attitude, it should be realized that the magnitude of the lifting forces and their effect will be a function of the particular design of the body, the location of the exit ports and conduits, and the speed of the towed body through the water.

Obviously many modifications and variations of the present invention are possible in the light of the above teachings. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.

What is claimed is:

1. A self-contained system for depth control of a sub submerged towed body, comprising:

a fluidic amplifier mounted in said body and having an inlet in the flow stream of the body;

said fluidic amplifier having a plurality of exit conduits;

a first of said exit conduits terminating on the surface of said submerged body in a first exit port and a second of said exit conduits terminating on the surface of said submerged body opposite to the termination of said first conduit, in a second exit port;

a regulator connected to said amplifier and having an inlet in said flow stream, providing control fluid to said amplifier for diverting the stream entering said fluidic amplifier to said first or second exit conduits to alter the body attitude;

said first and said second exit ports being in the region of flow separation; and

said exit ports are shaped to entrain said fluid along the side of said body aft of the exit port and causing the flow stream separation point to move further aft along said body and increasing the lifting force on the body for altering its attitude.

2. The system of claim 1 wherein:

said first exit port is on the top of said body;

said 3 second port is on the bottom of said body; and

including a pressure transducer connected to said regulator for sensing a variance of body depth from a predetermined depth;

said regulator emitting a control stream to divert said flow stream to said second conduit in response to a sensed pressure higher than said predetermined depth pressure for diverting said entering stream to said second exit conduit and producing a force on the bottom of said submerged body;

said regulator directing a control steam to said fluidic device in response to a sensed pressure lower than said desired pressure and diverting said entering stream to said first exit conduit and producing a force on the top of said submerged body; and

said force on said bottom of said submerged body forcing said body into a surfacing attitude to decrease the depth of said submerged body and said force on said top of submerged body forcing said submerged body into a dive attitude to increase the depth of said submerged body.

3. The system of claim 2 comprising:

a spoiler conduit connected from said first exit conduit to said bottom of the submerged body and terminating in a spoiler port on the bottom of said submerged body and adjacent to said second conduit outlet;

a second spoiler conduit connected to said first exit conduit to a point on the top of said submerged body, and terminating in a spoiler port on the top of said body and adjacent to first conduit exit port;

each of said spoiler conduits diverting a portion of its respective exit conduits stream; and

each of said spoiler ports directing its stream opposite the direction of said flow stream for increasing the flow stream separation from said body.

4. The system of claim 3, wherein:

said regulator is a proportional flow regulator for emitting a control stream proportional to the variance in sensed pressure from said predetermined depth; and

said fluidic amplifier is a proportional flow amplifier and includes a third exit conduit connected to a third exit port for conveying said incoming stream through said body, in the absence of control fluid emitted by said regulator.

5. A self contained system for depth control of a submerged towed body, comprising:

a fluidic amplifier mounted in said body, having an inlet in the flow stream of said body, and having a first, second and third exit conduits terminating in the stern of said submerged body;

a regulator connected to said amplifier, and having an inlet in said flow stream for providing control fluid to said amplifier for diverting the stream entering said fluidic amplifier to one of said first, second or third exit conduits;

a first intake conduit connected to said fust exit conduit;

said intake conduit having an opening at the upper surface of said submerged body within the flow separation region;

a second intake conduit connected to said second exitconduit and having an intake at the bottom surface of said submerged body in the flow separation region;

said regulator having a pressure sensor for sensing the variance in depth of the body from a predetermined depth;

said regulator directing a control stream to said fluidic amplifier when said sensor senses a pressure greater than the desired pressure for diverting said entering stream to said second exit conduit;

said second exit conduit stream creating a lower pressure in said second intake conduit and drawing fluid into said second intake conduit from said flow separation region for moving the flow separation point further aft along the surface of said submerged body and increasing the lift along said bottom surface of said submerged body;

said regulator directing a control stream to said fluidic amplifier when said sensor senses a pressure lower than said desired pressure for directing said entering stream to said first exit conduit;

said first exit conduit stream creating a low pressure in said first intake conduit for drawing fluid in from said separation region surrounding said first intake conduit, for moving said separation point further aft and increasing lift along said upper surface; and

said increased lift along said lower surface changing said submerged body attitude to a diving attitude and said increased lift along said lower surface changing said submerged body attitude to a surfacing attitude.

k l t i 

1. A self-contained system for depth control of a sub submerged towed body, comprising: a fluidic amplifier mounted in said body and having an inlet in the flow stream of the body; said fluidic amplifier having a plurality of exit conduits; a first of said exit conduits terminating on the surface of said submerged body in a first exit port and a second of said exit conduits terminating on the surface of said submerged body opposite to the termination of said first conduit, in a second exit port; a regulator connected to said amplifier and having an inlet in said flow stream, providing control fluid to said amplifier for diverting the stream entering said fluidic amplifier to said first or second exit conduits to alter the body attiTude; said first and said second exit ports being in the region of flow separation; and said exit ports are shaped to entrain said fluid along the side of said body aft of the exit port and causing the flow stream separation point to move further aft along said body and increasing the lifting force on the body for altering its attitude.
 2. The system of claim 1 wherein: said first exit port is on the top of said body; said 3 second port is on the bottom of said body; and including a pressure transducer connected to said regulator for sensing a variance of body depth from a predetermined depth; said regulator emitting a control stream to divert said flow stream to said second conduit in response to a sensed pressure higher than said predetermined depth pressure for diverting said entering stream to said second exit conduit and producing a force on the bottom of said submerged body; said regulator directing a control steam to said fluidic device in response to a sensed pressure lower than said desired pressure and diverting said entering stream to said first exit conduit and producing a force on the top of said submerged body; and said force on said bottom of said submerged body forcing said body into a surfacing attitude to decrease the depth of said submerged body and said force on said top of submerged body forcing said submerged body into a dive attitude to increase the depth of said submerged body.
 3. The system of claim 2 comprising: a spoiler conduit connected from said first exit conduit to said bottom of the submerged body and terminating in a spoiler port on the bottom of said submerged body and adjacent to said second conduit outlet; a second spoiler conduit connected to said first exit conduit to a point on the top of said submerged body, and terminating in a spoiler port on the top of said body and adjacent to first conduit exit port; each of said spoiler conduits diverting a portion of its respective exit conduits stream; and each of said spoiler ports directing its stream opposite the direction of said flow stream for increasing the flow stream separation from said body.
 4. The system of claim 3, wherein: said regulator is a proportional flow regulator for emitting a control stream proportional to the variance in sensed pressure from said predetermined depth; and said fluidic amplifier is a proportional flow amplifier and includes a third exit conduit connected to a third exit port for conveying said incoming stream through said body, in the absence of control fluid emitted by said regulator.
 5. A self contained system for depth control of a submerged towed body, comprising: a fluidic amplifier mounted in said body, having an inlet in the flow stream of said body, and having a first, second and third exit conduits terminating in the stern of said submerged body; a regulator connected to said amplifier, and having an inlet in said flow stream for providing control fluid to said amplifier for diverting the stream entering said fluidic amplifier to one of said first, second or third exit conduits; a first intake conduit connected to said first exit conduit; said intake conduit having an opening at the upper surface of said submerged body within the flow separation region; a second intake conduit connected to said second exit conduit and having an intake at the bottom surface of said submerged body in the flow separation region; said regulator having a pressure sensor for sensing the variance in depth of the body from a predetermined depth; said regulator directing a control stream to said fluidic amplifier when said sensor senses a pressure greater than the desired pressure for diverting said entering stream to said second exit conduit; said second exit conduit stream creating a lower pressure in said second intake conduit and drawing fluid into said second intake conduit from said flow separation region for moving the flow separation point furtHer aft along the surface of said submerged body and increasing the lift along said bottom surface of said submerged body; said regulator directing a control stream to said fluidic amplifier when said sensor senses a pressure lower than said desired pressure for directing said entering stream to said first exit conduit; said first exit conduit stream creating a low pressure in said first intake conduit for drawing fluid in from said separation region surrounding said first intake conduit, for moving said separation point further aft and increasing lift along said upper surface; and said increased lift along said lower surface changing said submerged body attitude to a diving attitude and said increased lift along said lower surface changing said submerged body attitude to a surfacing attitude. 